Means for removing and replacing knives of paper cutting machines



7 3 S m 11 M i C 2 A M G N I T T U C R E P P F 0 S E V I N K G N I C. A L P E R D N A G N I V M E R R O. F S N A E M Feb. 14, 1939. :E. L. MUELLER Filed March 30, 1935 2 Sheets-Sheet l FIGHi Feb. 14, 1939. E. MUELLER MEANS FOR REMOVING AND REPLACING KNIVES OF PAPER CUTTING MACHINES 2 Sheets-Sheet 2 Filed March 50, 1935 R m E G V A m z i 3 1 0 I,

o0 .l f Y/ UH B a. Z 2 P F d IU W 0 My Q 6 v w 1 H a u 5 \T 6 a F ATTORNEY.

Patented Feb. 14, 1939.

N T WFFI MEANS FOR 'RE-MOVING AND REPLACING KNIVES OF PAPER oU'rmNe'MAomNEs '7 Glaims.

This invention relates to paper cutting machines which include a vertically movable knife bar to which a knife is detachably connected and a clamp'bar which clamps in place the paper to be cut by the knife, this clamp bar being vertically movable so as to move it into clamping position upon the paper or remove it therefrom, the clamp bar and knife bar being relatively movable, the invention being more particularly concerned with a means and method for removing or replacing the knife from or in operative position in the machine.

Heretofore devices for facilitating the insertion and removal of the knife have provided support- 7 ing means secured to the clamp bar. Thishowever is objectionable for many reasons among which may be mentioned the necessity for formation of holes in the clamping bar into which the knife supporting means is secured whereby the machine is mutilated in a manner objectionable to the manufacturers of the machine as Well as tothe users, there is danger of injury to the operators fingers by reason of entering into holes, etc.

It is the main object of the present invention to provide an improved means of the character as indicated which shall be based upon the bed of the machine, the knife being supported therefrom, a firm and reliable support being thereby provided and the objections incident to supporting the knife from the clamp bar are avoided.

A further object of the invention is to provide a knife support independent of the clamp bar whereby the mutilation of the clamp bar is unnecessary and it is left intact as put out by the manufacturer.

A further object of the invention is to provide means of the character as indicated which requires no modification or mutilation of the paper cutting machine whatever.

A further object of the invention is to provide a simple and efficient means of the character as described.

A further object of the invention is to provide an improved method for removing a knife from or replacing it in a paper cutting machine.

A further object of the invention is to provide a device of the character as indicated which may be operated in the limited space available in machine, partly broken away and certain vof the parts omitted for clearness, and of the improved -device of the present invention applied thereto.

Fig. 2 is an end View of the improved knife supporting device.

"Fig. 3 is a topplan View of the knife supportingdevice of Fig.2.

Fig.4 is a rear elevation of the device of Figs. 2 and 3.

Fig. 5 is a front elevation of the device of Figs. 2, 3 and 4.

Fig. -6 is' a-partial section on the line 6'-6 of Fig. 3.

"Fig. '7 is a fragmentary"perspective viewshowingamodified construction of the mounting of the-supporting yoke, and

"Fig. 8 is-a fragmentary view in section of a modified form of knife engaging support.

Referring to-the drawings,- and first to Figs. 1 tot inclusive, the paper cutting machine comprisesa bed lupon which the pile of paper to be cut islaid, and-an upright frame? within which are guided the verticallymovable clamp bar'3 and the knife bar4. The bars 3 and 4 are vertically movable independently and the bar 3-is adapted to be forcedagainst the top of the pile-of paper sheets,-which lie on the bed, while they are being cut and is movable upwardly to afford space -for-the insertion or removal of a pile of sheets. The bars has a rabbett 5 at itsloweredge :within which is secured the knife 6 by-means of thescrews l. The front lower edgeiof the knife 61s bevelledat B and terminates in the :very sharp cutting edge ll, the knife bar and its knife sliding on the surface of the clamp bar 3 as the knife bar and knife are vertically reciprocated. The-clamp barisnormally held in elevated position by means of a strong spring and is moved into clamping position against the force of the spring bymeans of a lever not shown as this is o1d-..and.well understood. The knife bar is actuated by a suitable: motor mechanism under the control of the operator which is also old and :well .known .and consequently is not shown in ithe drawings and requires. no further description. The papercutting' machine as thus far described is old and well. known.

The knives :of suchmachines because of dullness, mutilation or other causes require to be removed from the machine from time to time so as to be-replaced,- sharpened or otherwise cared for. The removal-and insertion of the knife is not a simple matter when it is taken intoconsideration that the knife is .very heavy,=weighing pounds danger of damage to the operator or to the knife. The present invention supplies a safe and eflicient means for handling the knife during these operations and in an illustrative form is described as follows in connection with Figs. 1 to 6 inclusive:

The means for handling the knife comprises a base In adapted to rest on the upper surface of the bed I of the paper cutting machine, wherefrom extends a vertical upright plate II, and to provide a broader base and thereby give the device greater stability, projections I2 extend from the front of the plate I I with their lower extremities in the plane of the bottom of the base ID.

Extending rearwardly from the vertical plate I I is a horizontal plate I3 in which one end of a shaft I4 is rotatably mounted, the other end of r the shaft being rotatably mounted in the base Ill. The shaft I4 has screw threads I5 for the greater portion of its length and fixed upon the shaft is a worm wheel I6 co-operating witha worm I'I fixed upon a shaft I3 journaled in the base I0. Also fixed upon the shaft I8 is a spur gear I9 adapted to mesh with another spur gear 20 fixed upon the end of a shaft 2I having a hand crank 22 at its end, the shaft 2I being sufficiently long so that the handle will be outside the front edge of the bed of the machine, so that it can be turned, and the other end of the shaft having a socket inside the gear 20 for receiving the cylindrical pin 20 extending from the plate I I, the pin I forming a bearing for the inner end of the shaft as it is turned. The shaft I4 extends through a hole in the rearwardly extending projection 23 from a cross head 24 comprising a plate 25 sliding in rabbets 26 and 21 extending along the vertical slot 28 in the upright plate II and also the integral projection from the plate 25 extending within the slot 28. The cross head 24 is secured to the projection 23 by means of screw 29. Tapped in the hole in the projection 23 through which the shaft I4 extends, are threads which engage with the threads I5 so that as the shaft I4 is turned in'the manner. as described, the projection 23 and its connected cross head will be moved up or down according to the direction of turning and the cross head will slide in and be guided by the walls of the slot 28 and the rabbets along the edges thereof. Mounted upon the projection 23 and movable up and down therewith is a yoke 3| extending about the sides of the plate II and to the front ends thereof are secured the knife supports 32 and 33 overlapping the front of the plate II and having the bevelled surfaces 34 and 35 conforming to the bevel of the knife to be supported and therebeing slots 36 and 3! cut in the supports 32 and 33 at the bottoms of the bevelled surfaces. Clearances are thus provided which prevent the supports from coming against the knife edge in such manner as to dull or injure the same.

The yoke 3I is rockably mounted upon the projection 23 by having a recess. 38 at substantially the middle portion of the yoke which embraces the projection 23 and a reduced portion 39 of the projection 23 enters the hole 38 in the yoke and forms a rocking bearing therefor,the shoulders 40 upon the projection 23 coming against the yoke to limit the movement of the projection 23 and cross head 24 in a forward direction.

It is of advantage for the yoke to be free to tilt longitudinally so that the supporting surfaces It is therefore difficult to handle the knife and lowest at the left hand of that figure.

32 and 33 may automatically adjust themselves to the knife and accordingly the yoke 3| may rock upon the projection 23. This tilting movement is however limited by a pin 4I fixed in the yoke and having a hole into which'extends a pin 42 fixed in the projection 23, there being suflicient clearance in the hole about the pin 42 to permit the tilting movement referred to but preventing tilting beyond certain limits. Also clearances 43 and 44 are provided between the edges of the plate II and the ends of the yoke to permit the tilting referred to. The pins M and 42 might be omitted by making the portion of the projection 23 of square cross section where it is embraced by the recess 38 and making the recess 38 in the yoke 3I also square but with sufficient clearance to permit a certain amount of tilting of the yoke. Under such circumstances the tilting would be limited by the sides of the yoke recess coming against the sides of the square portion of the projection 23. Such a construction is shown in Fig. 7 wherein the yoke 3| has a square recess 38 embracing the projection 23 at the flat sided portion 39 It will be obvious that this permits a tilting of the yoke 3I about the axis of the projection 23 but that this tilting is limited in each direction by one side or the other of the recess 38 coming against a fiat side of the projection 23.

It will be observed that, in order to facilitate the cutting of the paper by the knife, the knife edge 9 is inclined from one end to the other being highest above the bed at the right hand of Fig. 1 The yoke 3i will therefore be normally inclined to correspond with the inclination of the knife edge so that one of the supporting members as 32 will be at a somewhat higher level than the other supporting member 33 so that the inclined knife will rest simultaneously upon these members, any slight adjustment to achieve this result being automatically accomplished by the tilting of the yoke upon the member 23 as before referred to.

In removing a knife, the clamp bar is caused to assume its raised position and the knife bar is caused to assume a position with its edge slightly below the lower edge of the clamp bar. The supporting means is then placed on the surface of the bed I and on account of the fact that the vertical plate I I is made as high as possible it may be slid endwise under the highest end of the knife (at the right in Fig. l). The support is then swung into position such that the plate II is parallel to and its front face is substantially in alignment with the back surface of the knife. The operating bar 2| with its hand crank is then placed in position by sliding the gear 29 into mesh with the gear I9, the pin 20 at the same time entering into the socket within the gear 20. The handle 22 being then turned the supports 32 and 33 will be moved upwardly into engagement with the front inclined or bevelled face of the knife, the back vertical face of the knife resting against the front vertical face of the plate II whereby the knife is supported between the supporting means 32 and 33 and the plate II. The screws I, securing the knife to the bar 4, are then removed and the knife is lowered by lowering the supporting means 32 and 33 by turning the handle 22 in the appropriate direction, until the knife has cleared the knife and clamp bars. The knife and support may then be swung in a horizontal plane to clear the knife of the side guides and then the support and knife together can be moved forwardly of the bed into a position where the knife may be conveniently taken hold of by the operator to remove it from the support. During these entire operations it will be observed the knife is supported on the upper face of the bed plate and the knife is much more conveniently handled by having it moved in its support to a convenient position at the front of the bed plate than was the case when the operator was obliged to extend his arms to lift it from its position adjacent the clamp and knife bars as was necessary with prior methods of removing or replacing a knife. For convenience in laying hold of the knife by the operator, handle bars 45 and 45 may have their threaded ends screwed into the tapped holes in the knife 6 which are provided for the securing screws 1.

In inserting or replacing a knife the support may be placed on the machine bed adjacent the front thereof and the knife placed in position between the supporting means 32 and 33 and the plate l I. The support carrying the knife is then pushed backwardly upon the bed surface until the knife is in position below the knife bar. The operating rod 2| is then placed in'position and the supports 32 and 33 are raised until the knife has been raised into securing position with regard to the knife bar. The screws 7 are then inserted and the supports 32 and 33 lowered sufficiently to permit the supporting device to be removed. It will be observed that during this entire process of inserting the knife it is supported upon the surface of the bed plate.

The supporting means as 32 and 33 may have adjusting means whereby the supporting means may be adjusted to the knife if they should not be supporting means 32 corresponding to the means 32 and 33 of Fig. 1, has screwed therein an adjusting screw 41 which by turning it in one direction or the other may be adjusted to come against the bevelled or inclined face 8 of the knife and support the same at different distances from the inclined or bevelled face 35 as may be required. The screw 4'! may be locked in any position of adjustment by means of a lock nut 43.

While the invention has been illustrated in what are considered its best applications, it may be embodied, in other structures without departing from its spirit and is not therefor limited to the structures shown in the drawings.

What I claim is:

1. In a device of the character described, the

combination with a base adapted to rest upon the bed of the paper cutting machine, of a plurality of horizontally spaced knife supports vertically movable on the base, providing clearance for preventing abutment against the cutting edge of the knife, and means for moving said supports vertically and simultaneously to raise and lower the knife, said base and supports constituting a unitary structure, in all positions of said supports, movable as such toward the knife, preliminary to its removal, and movable with the knife, when carried upon the supports, both for removal and replacement of the knife.

2. A device of the class described, having the features claimed in claim 1, in which each of said vertically movable knife supports is provided with a forward portion bearing against the forward bevelled edge of the knife and another portion bearing against the vertical back of the knife, thereby co-ordinating the movements of the ends of the knife in a plane parallel to the broadside thereof.

3. A device of the class described, having the features claimed in claim 1, in which provision is made of means for moving said supports vertically in unison to raise and lower the knife each of said supports having a forward portion bearing against the forward bevelled edge of the knife and another portion bearing against the vertical back of the knife.

4. In a device of the character described, the combination with a base having a stationary upright bearing against the vertical back of the knife and a plurality of horizontally spaced supporting means forward of said upright between which and said upright the knife is adapted to rest, said supporting means being each vertically movable with relation to said upright, and means for moving said supporting means in coordinated relation to each other and to said base to carry the knife vertically with relation to said upright.

5. A device of the class described, and having the features claimed in claim 4, in which each of the knife supporting surfaces corresponds to the inclined forward face of the knife, leaving the knife edge free from contacts.

6. In a device of the character described, the combination with a base having a stationary vertical plate bearing against the vertical back of the knife and supporting means forward of said plate between which and said plate the knife is adapted to rest, said supporting means being vertically movable with relation to said plate, and means for moving said supporting means, said supporting means comprising a plurality of separated knifesupporting surfaces and being tiltably supported whereby it may tilt to adjust itself to the supported knife.

7 A device of the class described for assembling and demounting a knife with relation to the knife plate and clamp bar of a paper cutting machine of the type having a feeding bed intersecting the vertical cutting plane, said device comprising a base adapted to rest upon and slide across said bed under the knife plate and clamp bar, and a pair of vertically movable supporting means mounted as a unitary structure with said base and adapted to receive the knife and carry it selectively toward and away from the vertical cutting plane.

EMIL L. MUELLER. 

